| // Copyright 2008, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "base/process.h" |
| #include "base/logging.h" |
| #include "base/process_util.h" |
| #include "base/scoped_ptr.h" |
| |
| bool Process::IsProcessBackgrounded() { |
| DCHECK(process_); |
| DWORD priority = GetPriorityClass(process_); |
| if (priority == 0) |
| return false; // Failure case. |
| return priority == BELOW_NORMAL_PRIORITY_CLASS; |
| } |
| |
| bool Process::SetProcessBackgrounded(bool value) { |
| DCHECK(process_); |
| DWORD priority = value ? BELOW_NORMAL_PRIORITY_CLASS : NORMAL_PRIORITY_CLASS; |
| return (SetPriorityClass(process_, priority) != 0); |
| } |
| |
| // According to MSDN, these are the default values which XP |
| // uses to govern working set soft limits. |
| // http://msdn.microsoft.com/en-us/library/ms686234.aspx |
| static const int kWinDefaultMinSet = 50 * 4096; |
| static const int kWinDefaultMaxSet = 345 * 4096; |
| static const int kDampingFactor = 2; |
| |
| bool Process::ReduceWorkingSet() { |
| if (!process_) |
| return false; |
| // The idea here is that when we the process' working set has gone |
| // down, we want to release those pages to the OS quickly. However, |
| // when it is not going down, we want to be careful not to release |
| // too much back to the OS, as it could cause additional paging. |
| |
| // We use a damping function to lessen the working set over time. |
| // As the process grows/shrinks, this algorithm will lag with |
| // working set reduction. |
| // |
| // The intended algorithm is: |
| // TargetWorkingSetSize = (LastWorkingSet/2 + CurrentWorkingSet) /2 |
| |
| scoped_ptr<process_util::ProcessMetrics> metrics( |
| process_util::ProcessMetrics::CreateProcessMetrics(process_)); |
| process_util::WorkingSetKBytes working_set; |
| if (!metrics->GetWorkingSetKBytes(&working_set)) |
| return false; |
| |
| |
| // We want to compute the amount of working set that the process |
| // needs to keep in memory. Since other processes contain the |
| // pages which are shared, we don't need to reserve them in our |
| // process, the system already has them tagged. Keep in mind, we |
| // don't get to control *which* pages get released, but if we |
| // assume reasonable distribution of pages, this should generally |
| // be the right value. |
| size_t current_working_set_size = working_set.priv + |
| working_set.shareable; |
| |
| size_t max_size = current_working_set_size; |
| if (last_working_set_size_) |
| max_size = (max_size + last_working_set_size_) / 2; // Average. |
| max_size *= 1024; // Convert to KBytes. |
| last_working_set_size_ = current_working_set_size / kDampingFactor; |
| |
| BOOL rv = SetProcessWorkingSetSize(process_, kWinDefaultMinSet, max_size); |
| return rv == TRUE; |
| } |
| |
| bool Process::UnReduceWorkingSet() { |
| if (!process_) |
| return false; |
| |
| if (!last_working_set_size_) |
| return true; // There was nothing to undo. |
| |
| // We've had a reduced working set. Make sure we have lots of |
| // headroom now that we're active again. |
| size_t limit = last_working_set_size_ * kDampingFactor * 2 * 1024; |
| BOOL rv = SetProcessWorkingSetSize(process_, kWinDefaultMinSet, limit); |
| return rv == TRUE; |
| } |
| |
| bool Process::EmptyWorkingSet() { |
| if (!process_) |
| return false; |
| |
| BOOL rv = SetProcessWorkingSetSize(process_, -1, -1); |
| return rv == TRUE; |
| } |
| |
| int32 Process::pid() const { |
| if (process_ == 0) |
| return 0; |
| |
| return process_util::GetProcId(process_); |
| } |
| |
| bool Process::is_current() const { |
| return process_ == GetCurrentProcess(); |
| } |
| |
| // static |
| Process Process::Current() { |
| return Process(GetCurrentProcess()); |
| } |